Relentless heat takes a bite out of the bounty of backyard tomatoes this year

Add another victim to the casualties of the drought: backyard tomatoes. These are usually the salad days, the happy time of year we should be swimming in the red fruit, delighting our neighbors with gifts on their doorsteps, making sandwiches with slices as thick as a T-bone.

But not this blue-blazing summer.

Tomatoes get fat and happy on warm days between 75 and 85 degrees and nights around 60 in the high desert. This diurnal pendulum gives tomatoes and melons their rich, sweet flavor. There’s no replacing the sun’s touch, which is why store-bought, grow-light tomatoes taste like damp Styrofoam to my homegrown-cultured palate.

As with humans, tomatoes don’t want to do much when it’s as hot as it’s been, including reproduce, scientists have reason to believe.

“The reproductive (gametophytic) phase in flowering plants is often highly sensitive to hot or cold temperature stresses, with even a single hot day or cold night sometimes being fatal to reproductive success,” wrote Kelly E. Zinn, Meral Tunc-Ozdemir and Jeffrey F. Harper in a 2010 article in the Journal of Experimental Botany.

Colorado State University’s Master Gardeners have cooler heads about hot reproduction: “If the daytime temperature reaches 90°F by 10 a.m., blossoms that opened that morning abort,” they warn, noting that with the right balance of watering, mulch and sweetened soil, tomatoes can grow quite large in high heat. Clearly, I did not water or till appropriately, because my harvest to date looks like a few red ping-pong balls, during a time I should be slicing softball-sized champions (that prove me to be botanically superior to my neighbors).

Abnormally hot weather, without a doubt, is a welcome sign to blossom end rot, hornworms and sun scald, common enemies emboldened by the scorched, weakened plant.

Plant ‘em in the spring, eat ‘em in the summer,
All winter without ‘em is a culinary bummer.
I forget all about the sweatin’ and diggin’
Every time I go out and pick me a big ‘un.

Sad as that may be — and trust me, I’m sad — let’s be realistic. Denver needs just two more days above 90 degrees to tie the most ever in one year. So far, 59 days, nearly two full months, have recorded temperatures above 90, above the threshold that’s comfortable to tomatoes. The record is 61 set in 2000.

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